Thats a load of crap! I own a 06 GT Mustang, pure stock 5 speed and an 09 R/T 6 speed and I would say given most parameters (driver ability etc) that they could go either way. My wife drives the hell out a car and shes says the RT feels faster. I think the Mustang feels quick too so who knows, but Stock vs Stock its close with and edge to the R/T.